The Molecular Cytology Core will continue to provide a comprehensive state-of-the-art morphologic facility to study structure and function of liver cells. It will analyze chemical and antigenic properties of subcellular membrane compartments as well as the functional properties of subcellular compartments and their interrelationships. Light, electron and confocal microscopic techniques will be used to analyze the different levels of complexity of liver cells, in combination with methodologies that label specific macromolecules of the intra-and intercellular membrane systems and of the nucleus. Because of the variety of microscopes and in situ methods available in the facility, liver cells can be studied at different levels of organization, i.e., from their overall topology to their subcellular membrane properties and macromolecular composition in both the living and non-living state (after fixation). The advantage of analyzing liver cells by in situ procedures is that cellular and subcellular architecture is maintained and properties of membrane systems and their interrelations in intact cells can be directly observed in real time or as fixed by preservatives at specific times. This approach reveals information regarding the organization and function of membrane and cytoskeleton compartments in cellular events that may be lost when cells are fractionated. The Director of the Molecular Cytology Core has a broad background regarding the basic cell biological processes that occur in the liver. She provides the Program investigators with technical expertise and with valuable guidance in the design and execution of their studies. She also provides interpretation of the microscopic observations for investigators as required. The Director oversees the daily activities of the personnel in the Core as well as assigning them to specific projects as needed, according to their expertise.